......

 

Oh really....
did you take into account that DIFFERENT fuels (gasoline vs. LPG) have DIFFERENT air/fuel requirements?

I don't know about the CNG Dodge, I have only spoken for LPG powered, standard gasoline engines, in general.
I have no experience with CNG cars, but more than 10 years of driving LPG cars myself and _knowing_ the "story behind", without having to read wikipedia...
If you don't trust a mechanical engineer, go read some LPG related forums. There is NO power loss using LPG (except on venturi mixer style systems, because of restricted air intake by the venturi, but these are 1990s history...). There is power INCREASE using LPI (liquid LPG injection) because of the intercooler effect of the vaporizing gas, even with not-modified engines.

You don't have to "like" LPG powered cars (I would also prefer to let the V8 guzzle cheap pump gas if I were in the States), but at LEAST respect the facts and don't scare people off LPG conversions with your fake facts. Do YOU own a LPG car? No? Then please, stop spreading nonsense about them.

Thanks

 

CNG is very different than LPG. I don't know much about either but I do know CNG is stored at a much higher pressure than LPG as I've seen both tanks. I also know you need a much bigger orifice when converting a BBQ from propane to natural gas because of the energy concentration.
Put these two concepts together and you realize the fuels may all burn in the same engine but trying to say they are pretty much the same is futile.
Up North LPG is pretty much gone as an engine fuel. You could not possibly travel with it as all of the 1000 gal LPG tanks for refills have been replaced with trade-in 20 lb tanks. My van has a 30 lb tank under it and I have to search around to get propane for it, most people dispense by weight rather than litre but that doesn't work since they can't weigh my van.
Steve

 

I have 70+80 Liters (2 tanks) under my van... that's roughly 120lb of LPG (80% charge) :-) That drives me some 300 miles... would be more, but I have removed the fuel tank to get 2 tanks under the van, so I have no "spare". If it's empty, there is no jerry can to refill

Yes, the different orifice for different gasses, I know. Have converted a home stove the other way. But it's mainly a question of pressure, at least here. Methane (natural gas) at home has only 10 or 15 mbar over here, whereas propane is usually 30 or 50 mbar. That's why the propane orifice is much smaller.
Storage is at high pressure, because it does not liquify at reasonable pressure / temperature. It's stored as a gas at 200 or 300 bar... LPG just around 8 bar, liquid...